I asked my dr about that recently, and she said many people are able to tell if their glucose is rising or falling. When mine lowers, I feel a sensation too abstract to describe, but I have felt like I was starting to sweat at times. When it rises, I feel several sensations, again difficult to find descriptive terms, but the closest I can come to is a buzzing or hyper feeling. At the onset of rising glucose, I sometimes feel an odd, brief euphoric feeling. (I'm not on any medication or insulin yet that could lower my glucose to dangerous levels. Just on Metformin and Januvea.)

Consider yourself lucky to have symptoms. Many people have sweating, dizziness, and a few other symptoms of low blood glucose (hypoglycemia), however, very few have recognizable symptoms for hyperglycemia (high blood glucose). Learn to recognize these and heed the warnings. Also learn to test when this happens. The extremes are both serious and can be fatal if ignored.

I feel hungry and as if a switch has been thrown when I get lowish. But actually the only way to really tell is by testing. I have sometimes felt really really hungry, only to find that my bg is more than 5.5mm. You can get 'false hypos' so the best thing is to test before eating anything to correct them. If they are false, best not to eat anything. The body gets used to normal lower levels over a matter of time.

I have type 2. Until I started taking insulin I had some high BG episodes but never low. When my BG gets high I just feel sleepy. Now I am taking insulin I have low episodes. I start to sweat and am shaky. I get to have a small sweet treat! Whenever I break out in a sweat I test immediately.